1. Field of the Invention
The present invention relates to a device designed to minimize pain associated with the plantar fascia.
2. Related Art
The plantar fascia is a fibrous connective tissue that supports the arch of a foot. FIG. 1 illustrates a simplified diagram of a plantar fascia 100. As shown, the plantar fascia 100 extends from the proximal phalanges 102 of the toes to the calcaneal tuberosity 103 of the heel. The plantar fascia 100 includes three major components: the central component 101, the lateral component 104, and the medial component 105. Chronic overstressing of the plantar fascia can lead to inflammation, tearing, and/or shortening of this tissue. The resulting condition is called plantar fasciitis, which can cause severe foot pain. Although the central component 101 of the plantar fascia is generally considered the primary source of plantar fasciitis, both the lateral component 104 and the medial component 105 can also contribute to this painful foot ailment.
Various devices have been proposed to alleviate the pain associated with plantar fasciitis. For example, U.S. Pat. No. 6,110,078, issued to Dyer on Aug. 29, 2000, teaches positioning the heel of the foot at the “V” of two hinged plates and securing the foot in this position to one of the hinged plates using a strap. A spring and cinching device, which are attached to the open ends of the two plates, can then be pulled together to increase tension in the plantar fascia. An optional arch support and toe support can be provided to enhance the stretch of the plantar fascia.
The Dyer stretching device has several significant disadvantages. For example, the toe support provides a single angle of inclination, thereby ignoring the difference in flexibility of peoples' toes. Moreover, the arch support is in a fixed position, and therefore provides only general pressure against the plantar fascia. Yet further, the stretching device has many components, thereby undesirably increasing manufacturing cost and complexity of assembly.
U.S. Pat. No. 5,087,036, issued to Cooper on Feb. 11, 1992, partially solves the fixed toe support problem by providing a foot plate on which the heel and ball of the foot rests. An adjustable toe plate, on which the toes of the foot rest, is hinged to the foot plate. A support arm, which is pivotably attached to the toe plate, can engage with a selected groove in the foot plate to position the toes at an inclined angle.
The Cooper stretching device also has several significant disadvantages. For example, to achieve maximum benefit from the device, a user must be standing. Moreover, although the plantar fascia is under tension when the foot is positioned in the device, no pressure is provided on the plantar fascia by the device.
U.S. Pat. No. 5,399,155, issued to Strassburg et al. on Mar. 21, 1995, teaches a sock that includes an inelastic reinforcing strap and a “D” ring that are positioned approximately at mid-shin above the user's calf. A second, tapered inelastic strap is attached to the toe end of the sock. A hook and loop assembly, which is attached to the opposite end of the tapered inelastic strap, can be pulled through the “D” ring and then secured at the desired angle of toe inclination.
Although providing flexibility of toe inclination, the Strassburg stretching device still has several disadvantages. For example, the user must put a sock, which may be inconvenient. Moreover, the sock must be periodically washed, thereby requiring regular user maintenance. Yet further, although the plantar fascia is under tension when the hook and loop assembly is secured in the device, no pressure is provided on the plantar fascia by the device.
Therefore, what is needed is a device that can provide multiple angles of inclination, directed pressure against the plantar fascia, as well as ease of manufacturing and assembly.